Line grounding clip



March 5, 1946. H. E. WEBB LINE GROUNDING GLI? Filed Oct. 30. 1941 Wbb GPatented Mar. 5, 1946 um: GnoUNnmG om Harold E. Webb, Burbank, Calif.,assignor to Adel Precision Products Corp., a corporation of CaliforniaApplication October 30, 1941, Serial No. 417,077

4 Claims.

This invention relates to a support for metallic conduits of thecharacter employed on aircraft and particularly pertains to improvementsin the type of line supporting clip set forth in my copendingapplication for United States Letters Patent Ser. No.l412,783 filedSept. 29, 1941, which has matured to Patent No. 2,338,145 dated Jan. 7,1944, and also of the type set forth in United States Letters Patent No.2,215,283 issued to Paul W. Adler under date of September 17, 1940.

Conduit supports towhich the invention pertains are characterized by theprovision of a cushioned seat for a conduit carried by a metallicsupporting strap together with a bonding or grounding strip ofelectrically conductive material interposed between the cushioned seatand av metallic conduit supported therein and electrically connected tothe metallic strap which in turn is electrically connected to themetallic frame of the air craft so as toy prevent the accumulation ofstatic electricity in the line or conduit.

`It is important in devices of this character to provide adequateelectrical interconnection between the bondingstrip and thesupportingstrap and the primary object of the present invention is to provide sucha connection.

Another object is to provide a construction whereby the bonding stripmay be positioned to extend on opposite sides of the cushioned seat sothat a portion thereof will extend between said seat and the conduitthereon and another portion extend between said seat and the supportingstrap without passing the bonding strip through the cushioned seat asheretofore commonly practiced and thus facilitating construction andassemblage of the support.

With the foregoing objects in view, together with such other objects andadvantages as may subsequentlyv appear, the invention is carried intoeffect as illustrated by way of example in the accompanying drawing, inwhich:

Fig. 1 is a perspective view in vertical section of the clip showing itas applied and with portions broken away;

Fig. 2 is a view in vertical section of the clip showing it as applied;

Fig. 3 is a view in cross section taken on the line 3--3 of Fig. 1 asseen in the direction indicated by the arrows;

Fig. 4 is a detail in cross section taken on the line 4 4 of Fig. 2;

Fig. 5 is a perspective view of the clip with portions broken awayshowing it as'detached.

Referring to the drawing more specifically A indicates generally ametallic conduit supporting strap here shown-as in the form of a loopand as having an intermediate arcuate portion 1 merging at one end in astraight tangently extending end portion 8 terminating in an outwardlyolf-set ear 9 while the other end of the arcuate portionl merges into atangently ex-- tending straight portion I0 ending in an angularlydisposed ear II adapted to overlie and seat on the off-set ear 9.

The ears 9 and I I are formed with apertures I2 and I3 respectivelyadapted to be positioned in register with each other when the ear II isseated on the ear 9 and which apertures are designed to receive a boltI4 by which the strap may be secured to a metallic frame member I5 withthe olf-set ear -9 seating on the latter.

Extending over the inner face of the arcuate portion 1 of the strap andprojecting `along the tangential straight portions 8 and 9 is acushioning seat B formed of a suitablepresilient material such asneoprene, rubber, or` the like, and which cushioned seat may be amxed toand carried by the strap A in any suitable manner. As here shown thecushioned seat is formed of a strip of material of channelled crosssection and having ar T-slot I1 extending throughout lthe length thereofin which'the strap A is positioned with the open side of the T-slot I1extending along the outer periphery of the strap A. The cushioned seatthus extends over substantially the entire inner surface of the loopedportion of the strap and alsoaround the edges thereof.

The tangentialvend portion 8 of the strap is formed with alongitudinally extending reinforcing rib I8 projecting in continuationof the connected portion of the ear 9 intermediate the edges of thestrap, the outer face of which rib is adapted to seat on thevframemember I 5 as shown in Fig. 2 and the inner face of which rib iscontoured to provide a longitudinally extending recess I9 on the innerface of the tangential end portion 8 of the strap and which recess I9underlies a substantial length of the contiguous end portion of thecushioned seat B.

A thin flat strip C of electrically conductive metal is arranged with aportion thereof overlying the inner periphery of the cushioned seat B toeffect electrical contact with a metallic conduit D imposed on the seat,and having another portion in electrically conductive contact with thestrap A so as to act as an electrical grounding or bonding connectionbetween the conduit D and the frame member I5 through the clip.

Generally considered the features of construction and arrangement aboverecited are old in the art-and broadly are not my invention; the essenceof my present invention residing in the provision of a highlyadvantageous way of constructing andmounting the electricallyconductiveor bonding strip C. In 'carrying out the invention the thinstrip C which is pliable is bent upon itself intermediate its endsproviding a bend a and portions b and c leading therefrom, thus forminga forkedstructure which is positioned astride either or both ends of thecushioned seat with the termination ofthe seat proximate the bend a andso that one portion b will overlie the inner periphery of the seat,while the portion c will extend between the seat and its encompassingstrap A.

By this arrangement an electrically conductive surface is provided on'the opposed faces of the cushioned seat leading over an end thereof andwithout passing through the seat as in constructions heretoforeemployed, thus obviating formation of holes in the cushioned seat andthreading of the conductor there through as now commonly practiced.

The strip C is formed of a width less than that of the cushioned seatand is centered relative to the latter so that its side margins will beinset relative to the side margins of the seat wh-reby when the strap Ais tightly clamped around a conduit D the strip will be impressedintothe faces of the cushioned seat with its edges abutted by portionsof the seat thus confining portions of the strip and thereby securelyholding it against displacement.

Each terminus of the cushioned seat may and preferably are thus equippedwith an electrically conductive or bonding strip. In applying thebonding strip to the end portion of the cushioned seat overlying the endportion 8 of the strap an outward extrusion 20 is formed on the outerportion of the strip contiguous the bend a which is arranged to protrudeinto the recess I8 on the strap and is formed to conform to the Wall .ofthe latter so as to provide an interlock between the strip and strapsuch as to hold the bent end portion of the strip protruding from theportion embedded from lateral shifting.

In order to effect positive electrical connection between the strip andthe strap a spot weld ZI is applied in a fashion to fasten the strip tothe strap. This weld 2i is preferably applied to the extrusion 20 toanchorthe latter in the recess I9. By reason of the interenga gement ofthe wall of the extrusion 20 with that of the recess I9 serving to holdthe strip against lateral displacement, the weld 2i will be protectedagainst rupture as might occasion on lateral stress being applied tothe. bonding strip and which stress occurs when threading the clip onthe conduit or threading the conduit through the clip in applying thelatter.

In applying the bonding strip C to the ends of the cushioned seat it maybe put in place by initially positioning a length of the strip alongone, side of the cushioned seat before applying the latter to the strapand when bending the strip around the ends of the seat and extending thethen free end portion along the other face of the cushioned seat; one ofthe lengths of the strip leading from the bend thereof being positionedin the channel I'I to extend along the bOttom thereof.

In assembling the clip the strap A is initially formed straight with theear 9 off-set and ear II bent outwardly; the strap being subsequentlybent into its looped or U-shaped form as shown in Fig. 5 afterapplication of the cushioned seat and the bonding strips thereto. Wherethe bonding strip is to be welded to the strap, which may notnecessarily be required, the strip in a substantially straight form islaid on the inner face of the strap with the end portion of the stripdesigned to` be interposed between the cushioned seat and the strapoverlying the latter lengthwise thereof with the other end portionextending outwardly from the end of the strap. The strip may then bereadily anixed to the strap by one or more spot w'elds 2| at anysuitable points along the overlying portion of the strip. Where thestrip is formed with the extrusion 20 and is to be welded to the strapthe end portion of the strip carrying the extrusion is first positionedon the inner face of thestrap with the extrusion seated in the recess I9and with the then outer end of the strip extending outwardly along theouter end portion 8 of the strap. The spot weld 2| may then bereadilyapplied to the extrusion 2li. The cushioned seat B is thenpositioned on the strap, it being initially disposed on the latter byinserting the strap in its straight formation sideways into the T-slot I1 in the cushioned seat. The outer end portion of the bonding strip C isthen bent inwardly to extend over the inner surfaces of the cushionedseat lengthwise thereof. The assembly is then bent around a mandrel toimpart a substantially U-shaped formation thereto as shown in Fig. 5.

In applying the clip to support a conduit a y desired number of theclips are initially threaded onto a conduit D with the clips in theiropen position as shown in Fig. 5, the clip assemblies being thus slidlongitudinally along the conduit such as to effect a slight abradingaction on the surfaces of the bonding strips presented to the conduitthereby effecting polishing of such surfaces and the removal of at leasta major portion of surface oxidation from the strips so as to insure godelectrical contact between the strips and the conduit when clamped onthe latter and which contact is essential to the proper grounding of astatic current.

On the clip being disposed at the desired position along the length ofthe conduit D the ears 9 and I I of the clip are brought toward eachother with the openings l2 and I3 therein aligned whereupon the bolt Ilis passed through the openings and engaged with the frame member I5;tightening of the bolt drawing the strap and the cushioned seat tightlyagainst the conduit and in a fashion to compress the cushioned seat andto impress the terminations of the portions a and b of the bonding stripinto the cushioned seat as before described thus securely binding thebonding strip in place.

It will be apparent from the foregoing that by the construction setforth I have provided an effective grounding connection between theconduit and the supporting strap around the cushioned seat interposedbetween the strap and conduit Without the necessity of passing thebonding strip through the cushioned seat and in a fashion whereby thebonding strip will be securely held in place.

While I have shown and described a. specific embodiment of theinvention, I do not limit myf self to the exact details of constructionand claims.` .e

changesand modifications of the parts and their .arrangements asoccasionfrnay require coming within` the meaning and scope of theappended I eiaim: A" y 1. In a line grounding clip embodying a metallicsupporting strap and a cushioned seatcarried by said strap and extendingalong the' inner periphery thereof; an electrically conductive stripbent intermediate its ends and positioned astride an end of saidcushioned seat with one of its end portions extending between said s eatand said strap and with its other end portion overlying the outer faceof said seat for interposition between said seat and a conduit irnposedon the latter to effect electrical connection between said conduit andsaid strap around the terminus of said cushioned seat, said strap beingformed with a longitudinally extending recess on its inner periphery,and an extrusion on said strip projecting into said recess to hold thestrip against lateral shifting relative to said strap.

2. In a line grounding clip embodying a metallic supporting strap and acushioned seat carried by said strap and extending along the innerperiphery thereof an electrically conductive strip bent intermediate itsends and positioned astride an end of said cushion/ed seat with one ofits end portions extending between said seat and said strap and with itsother end portion overlying the outer face of said seat forinterposition between said seat and a conduit imposed on the latter toenect electrical connection between said conduit and said strap aroundthe terminus ot said cushioned seat, said strap being formed with alongitudinally extending recess on its inner periphery, an extrusion onsaid strip projecting into said recess, and means effecting a positiveconnection between the extrusion of said strip and the-walls of saidrecess.

3. In a line grounding clip, a metallic conduit supporting strap havinga longitudinally extending recess on its inner periphery,an`electrically conductive strip bent intermediate its ends. anextrusion on said strip adjacent the bend thereof extending into saidrecess, and a cushion seat extending along the inner periphery of saidstrap having an end portion extending between the end portions of saidelectrically conductive strip and terminating adjacent the bend in thelatter, there being a positive connection between said extrusion and thewall of said recess.

4. In a line grounding clip, a `metallic line supporting strap, acushioned seat liningsaid strap, an electrically conductive strip havinga portion overlying said cushioned seat and ldisposed to contact aconduit seated on said seat and having another portion overlying an endof said cushion seat and extending between the latter and said strap,whereby said portions of said strip will be pressed into said cushion onclamping said strap around a conduit.

HAROLD E. WEBB.

